Method and apparatus for drawing sheet-glass.



IATIIINTIID JAN. 1, 1907.

1. W. PULBURN METHOD AND APPARATUS FOR DhAWING SHEET GLASS.

AIILIGATION FILED MAY Ill. 1904.

4 SHEETS-SHEET l.

EVANS FRIC HON CONE W TNESSES W 1. W.C()I.1HJHN. METHOD AMI) APPARATUS FOR DRAWING SHUNT GLASS.

AIILIUATIUH TIMI MAY 18, X004 4 BHIJETS-SIIIIBT 3.

' FRICTIO C NE PATENTED JAN.1, 1907.

I. W. COL-BURN.

METHOD AND APPARATUS FOR DHAWINQSHEBT' GLASS.

APPLIOATION FiLIIDMAYiB,1UO4.

l SHEETS-SHEET 4.

5T TUFPNE vs UNIT E l it'll/U, ES

PAT lfl NT OFFICE.

IltVlNG \Y. t'lUlillUltN. (7)!" l ltnh'hldh', llCNNSYlA ANlA.

Specification of Letters Patent.

Patented Jan. 1,] 907.

Application filed May 18, 1904- Serial No. 208,570.

To alt whom it may ammo-1t:

Be it known that I, lnvnvo W. CoLnUnN, a resident of Franklin, Pennsylvania, have invented a new and useful improvement in Methods and Apparatus for Drawing Sheet- Glass,wl1ich invention is fully set forth in the following specification.

This invention relates to the art of glassworking, and more particularly to the art of drawing sheets of glass from a molten mass,

In my application Serial No. 178,912, filed October 28, 1903, l have disclosed an apparatus for drawing a sheet of glass from a mass of molten glass and after it has emerged from the furnace subjecting it to the action of rollers so disposed on the opposite faces of the sheet that they act to grasp the sheet of glass between them and roll it toward its edges, and thereby serve to stretch the sheet and overcome the tendency which sheets of glass have during the drawing operation to rapidly narrow and finally draw to a string or thread.

The present invention relates to a means and rocess for drawing sheets of glass whereby t e sheets may be drawn of uniform width and the tendency of the glass to narrow and draw to a string or thread may be obviated Without the necessity of stretching the sheet or of grasping it between oppositely-disposed rollers in the manner described in my application before mentioned.

The objects of the invention, generally stated, are to provide an apparatus and process whereby a sheet of glass of any desired thickness within fixed limits and of uniform width may be drawn and whereby a sheet may be produced having a smooth and brilant surface free from waves or llaws, which ould injure the marketable quality of the product.

Vith these objects in view, the invention resides in the process of forming a sheet of glass from a mass of molten glass, which con- Sists in drawing a sheet from said mass in an upward direction and simultaneously drawg the molten glass to fOIlll the edges of said heet from the mass of molten glass outward or away from the central line of the sheet as the same is drawn in a vertical direction.

6 general outward direction of the plastic g s as it is drawn to form the edges of the sheet may take place along any outwardly d upwardly inclined line. Moreover, it has been found that when drawing a sheet of g ss the sheet is liable to crack or check during the drawing operation unless the sheet is kept sullieicntly hot after it has become set, and For this reason the invention provides the additional step of imparting heat to the sheet of glass after it has emerged from the molten glass and has been drawn of the desired width and thickness, to the end that the entire sheet may be completed before the first portions drawn have been cooled to a degree where cracking is liable to occur.

The invention also consists in means for drawing the sheet in a longitudinal direction from the mass of molten glass combined with means engaging the plastic or molten glass in the pot near the edges of the sheet and drawing it in an upward and lateral direction. These u )wardly and laterally drawing means may to (e various forms. Preferably they are in the form of horizontal rollers whose axes of rotation are at right angles to the longitudinal movement of the plane of the glass, the periphery of the rollers entering the surface of the plastic mass in the working pot and the revolution of the rollers being upward and outward from the medial line of the sheet, the two rollers therefore revolving in reverse directions. These rollers may be variously situated without departing from the invention, it only being necessary to so locate them that they shall act to give an upward and outward movement to the portion of molten glass that is to form the edge portion of the sheet; but for most uses, however,

the osition wherein the rollers are within the wor 'ing pot and low enough down to have the lower sides of their peripheries immersed in the mass of molten glass is preferred These laterally and upwardly drawing rollers may assume a great variety of forms, as that of a cylinder having a plain surface or a cylinder having a peripheral groove at the point where the plastic glass which is to form the edge of the sheet of glass is engaged thereby, or instead of a groove the roller may have a peripheral ridge running around it at the point where the plastic glass which is to form the edge of the sheet is engaged thereby.

i These examples of various forms which may be given to the roller illustrate the fact that the invention is not hunted to a articular form or forms of roller, as many ot or forms than those described will readily suggest themselves to those skilled in the art.

The invention also consists in a working chamber or pot containing a mass of molten glass and having a plurality of filling or glass- ICC receiving conduits with means for draw or openings combined mg a sheet of glass from the mass between said conduits or openings and lateral means for which lateral drawing means are also located between the two iilli of the working chain tage of this construction lies in ng conduits or openings her or pot. The advanthe fact that as additional glass is supplied to the working chamber or pot through ings the hottest glass will be at the sides, I

these conduit-openwhereas the cooler glass will be at the central ortion of the sheet as drawn, thereby greatly acilitating the successful production of a :5 sheet of glass of even width and thickness.

The hot ass may be ladled into the working pot through filling-in openings or may be conducted to the working pot by ing from the refining conduits leadorother heating furnace,

to the essential being that the hot glass shall he directed to the portions of the s eet oints from which the edge are drawn.

The invention also consists in providing a working chamber or of drawing laterally pot containing the mass molten glass combined with nteans for the sheet both therefrom, said working chamber or longitudinally and pot being provided with a top closure having a slot or opening '30 drawn, which top is or along the middle through which the sheet is depressed in the center part of the slot, so as to bring the cover down much closer to the surface of the mass of molten glass in the working pot than it is at edges of the sheet passtherethrough.

the

the points where The result of this is that the drawn sheet is exposed to the cooling influence of the atmos- 'phere at the center edges, thereby sooner than it is at the leaving the edges in a plastic as end that the lateral drawing means may have fiondition longer than the center, to t ore time to effectively tion.

The invention,

perform their funcfurthernore, consists, in

5 combination with the aforementioned elements, nieans for supplying heat to the sheet of glass aiter it has been withdrawn from.

the molten mass in the working pot and become set or partially set, to the end that the sheet niay niaintain a sufficiently high tererature during the operation of drawing,

and thereby avoid the tendency of the sheet by the cooling influence of to crack or check the MI osphere as it it drawn outward from.

5 5 the working pot.

Another in portant feature of the invention consists of independent ea ns for operating the longitndinally-drawing and the laterally-drawing 6: two sets of devices 1r ay I variable speeds, so

devices. to the end that the be each actuated at thatthe work ran 2*: av

adjust the operation of the two devices to suit the conditions 0 working pot and the drawn.

f the Fulton glass in the diameter of sheet to be drawing the shock:

The invention linall consists in the (oi l bination of (lcviris and details of titJllSll'llti tion which will be hereinafter more Slittjlllcally described, and then pointed out in the claims. The inventive idea involved in the abovci mentioned process may receive various extprcssions without losing its identity, and a variety of forms of apparatus may be e: l ploycd in practicing the process. .\loreovcr the inventive idea of cans and devices con l stituting the echanical part of the inven- 1 tion .1 av receive various echanical expressions, one of which is shown in the aceo. pat Irving drawings for the purpose of illustrating the invention. Said drawings, however, are for the purpose of iilustration only and not for the purpose oi defining the li 1.its or scope of the invention.

in said drawings, Figure 1 is a vertical sew tion on the line a b, Fig. 4, with parts shown in elevation. Fig. 2 is a transverse central section on the line i j, Fig. 3. Fig. 3 is atop plan view with the heating-box 1e...oved, and Fig. -t is a front elevation. Fig. 5 is a sectional detail of one of the rollers and associ ated parts, the section being tak n on the line 0 (i of Fig. 4. Fig. 6 is a section on the line cf, Fig. 5. Fig. 7 is a section on the line 9 h, Fig. 5. ligs. S and 9 are sectional details illustrating a n odified form. of lateral drawing-rollers.

Referring to the drawings, in which like nun erals indicate like parts, 1 is a working pot of am usual or suitable construction surrounded by a suitable furnace or fire-box 2, to which heat is supplied in any suitable way, as by burners 3 3, the products of co bustion being carried off by a suitable flue, as 4. The working pot 1 and the lire-box 2, as here shown, are closed at the top, the working pot, however, being provided with a plurality of tillin -openings 5 5, here shown as two in nuir; )er, which filling-openings consist of holes through the cover of the working pot, which holes register with upwardly-projecting necks or conduits situated at each end of the pot. Any suitable cover 6, supplied with a bail 7 for facilitating the handling thereof,

is provided to close the filling-openings a. The cover or top to the working pot has an openin or narrow slot 8 formed therein, throng i which the sheet of glass is drawn. The cover, as here shown, is depressed along the greater or central portion of the slot S, so as to approach very near to the surface of the molten glass within the working pot, while along each end of the slot the cover rapidly l rises, preferably in an arc-like form, so that x the edges of the glass pass through the slot at i pot and immediately under the arc-shap portions of the rover thereto are two rollers t) 9, whose axes ol rotation mel erabl e.\'- tend at, right angles to [he surfarv ol' the, sheet of glass as it is drawn through the slot. 'lhese rollers are located in such a position that. the peripheries thereof engage the molten mass and draw upwardl and outwardly the glass to form the edges of the sheet. Preferably the peripheries of the rollers are so located that they lie slightly within the. lateral edges of the sheet, though this is not essential. As here shown, these. rollers I S) are so located that their peripheries are i:nme-rsed to a greater or less extent within the mass of molten glass in the working pot. As before mentioned, the rollers may be of various formssueh, for example, as shown in Figs. 5, 8, or !)-thou ;'h the eonstruction shown in Fig. 2 is preferred. The rollers may be mounted in any suitable way and provided with any suitable mechanism for driving the same. As here shown, the ends of the rollers are polygonal in form to engage corresponding sockets 10, Figs. 5 and 6, which sockets are integral with or otherwise rigidly secured to shafts l1 and 12, turning in bearings 13, mounted on the framework of the machine as, for example, on the piers 14, Fig. 3. ()ne of the shafts 12 has secured rigidly thereto a crank 15, by which it is re volved, and also has keyed thereto a bevelgear 16, engaging a corresponding gear 17 Fig. 3, on shaft 18, revolving in bearings 19 19, also secured to the pier 14-. ()n the opposite end of the shaft 18 is a bevel-gear 20, en gagin a bevel-gear 21 upon the. shaft of the otheriaterall r-drawing roller 9. By revolving the crank it will be seen that the rollers 9 9 will be revolved in opposite directions, either inward and downward toward each other,orupward and outward from each ot her.

Referring to Figs. 1 and -l, 22 is the bait, which may be of any suitable construction, which bait is secured to the flexible eables'li by any suitable means, as by open rings 24 24, the cables being wound around a drum 25 on shaft 26, which shaft turns in bearings 27, supported above the nzaehine, and is driven by the drivinq-belt 28, Fig. 1, running to any suitable souree of power, preferably to an Evans friction-(one deviee, l f means of which a variable speed nut be imparted to the drum, to the end that the sheet of glass may be drawn more or less rapidly, as the exigencies of the operation may require. Referring to Figs. 1 and 4, 29 is a heating apparatus for heating the opposite faces of the sheet of glass after it has emerged from the slot 8 in the cover of the workingpot. As here shown, this apparatus is in the form of a box having slots 20 through its top and bottom and supported upon suitable brackets or standards 30 30, resting on top of the furmace. Heat is supplied to the fire-box by burners 31 31, placed on opposite sides therel of and preferably within the lower portion,

the fuel-supply being regulated by a snitable' Operation: The mohen or plastic glass in the pot l beiire brought to the proper heat and working condition and the bait 22 having been previously prepared so that the plast ie glass will adhere to it, it is lowered, by means of the. cables .23 and the drum 25, through the lire-box and the slot 8 in the top of the working pot and is allowed to stand in the molten mass until the glass has adhered lirmly to it. The burners 31 in the lire-box 291 being lighted, the bait is then started upward by means of the drum driven by the friction-cone, and simultaneously with the upward movement of the bait the rollers El 9 are started to revolve inan upward and outward direetioni. 0., in the direction indicated by the arrows on Fig. 2 the revolution of these rollers being continued in the directions indicated during the entire operation of drawing the sheet. As the bait is drawn upward the plastieglass at the lower end of the sheet will adhere to the rollers 9 9 and will be drawn outward therewith in the manner indicated in Fig. 2, thereby initially drawing, the sheet of a uniform width without the necessity of stretching it after it is drawn. Immediately after the central portion of the sheet is drawn it emerges from the slot 8 and is subjected to the cooling influence of the atmosphere, which is sutlicicnt to set the same, whlle the edges which are in contact with the rollers 9 9 remain within the hot workingpot a littl-e longer, and immediately after these edges have been drawn outward to the desired poim by the rollers they, too, pass through the slot 8 at a point higher up than the point wh re the central portion of the Slittt passed through the slot and are likewise. subjected to the eoolin; influence of the atmosphere during the traverse of the sheet from the slot 8 to the lower portion of the tire-box 29. During the passage of the shert through the tire-box sufficient heat is imparted thereto to insure it against liability to eraek or check during the further operation. This application of heat to the surface of the glass is not to be confused with the process of fireiinishing glass as heretofore practiced. as tlu re is no need [0 fire-finish glass drawn by the process herein described, the surface being of a perfectly smooth and brilliant character and presenting a beautiful luster. The sole purpose of the fire-box 29 is to aid in retaining or adding to the heat that is still in the glass after it has been drawn, and thus avoid the cracking of the glass during, the drawing operation. The sheet of glass having been drawn to the desired length, the direction of rotation of the rollers 9 9 is reversed, while the bait continues to move u ward, thus causing the sheet of glass to tpliclily draw to a cord or lllltiltl, \\l|i1'lt run he t';\. 'll severed with a eold iron or ('lll oil with slnars. This nnnnn-r of severing the sheel leaves l||e glass in the \iorlting pot in excellent ('lllltlltlttll for drawing another sheet. The lower end of the sheet of glass being detached from the mass of molten glass in the working pot, the sheet is raised high enough to clean the parts of the machine and is then swung to one side and low ered into a horizontal or other position on suitable supports for removal. The bait is then cracked oll by any of the well-known means employed in the art, and the sheet is ready for the usual process of annealing or other treatment. The operation may be reeated by attaching a second bait to the cxible cables 23 and proceeding as before.

It will be observed that the sheet of glass is )roduced of full width by a drawing act ion on ly and that once it emerges in sheet form front the mass of molten glass in the. pot (being drawn by the movements of the bait and rollers) it retains its width without the necessity of any stretching between compression-rollers or otherwise. This is important, since it. avoids the marring of the surface of the sheet by contact with stretching-rollers, thus leaving the surface of the entire sheet of the same brilliancy as when drawn. By the term drawing as used in the specification and claims herein is meant the act of pulling glass out of the conglomerate molten mass by the continuous movement away from said mass of the part already pulled.

While, as heretofore stated, the rolls 9 9 act as drawing means for drawing the glass from the molten mass to form the edge portions of the sheet, and thus maintain it to its full width without the necessity of any stretching action, such rolls nevertheless have, in addition to this drawing function, the function of imparting a more or less lateral or stretching strain to the sheet, as will readily be perceived by studying the action of the rolls as illustrated in Fig. 2, so that said rolls constitute means for drawing the mass of molten glass to form the side portions of the sheet and simultaneously stretching the sheet laterally, and this is accomplished without any portion of the mechanism coming in physical contact with the faces of the Sheet at the edge portions or otherwise. and therefore without marring the fine tire-finish due to the drawing action.

What is claimed is l. The method of forming a sheet of glass, which consists in preparing a mass of molten glass, and drawing the glass therefrom in sheet form, the drawing force being simultaneously applied in the directions of the sheets length and width.

2. The method of forming a sheet of glass, which consists in preparing a mass of molten glass, and drawing the glass therefrom in sheet form, the drawing l'orre being sinnllta neonsly applied in the tllt'tittlult ol' the sheets length and in the directions of its two edges.

1%. The method ol forming a sheet of glass, which consists in preparing a mass of molten glass, and drawing the glass therefrom in sheet form, the drawing l'oree being simultaneously applied in a vertical direction and transversely of the sheetv 4. The method of forming a sheet of glass, which consists in preparing a mass of molten glass, and drawing the glass therefrom in sheet form, the drawing force being simultaneously applied in the direction of the top and edges of the sheet.

.5. The method of forming a sheet of glass which consists in preparing a mass of molten glass, drawing the molten glass in the direetion of thc sheets length to form the middl-t portion of the sheet, and simultaneously drawing molten glass in the direction of the slicets edges to form the edge portions of the sheet.

(J. The method of forming a sheet of glass, which consists in preparing a mass of molten glass, and drawing the glass therefrom in sheet form, the drawing force being simultaneously applied in the directions of the sheets length and width, and subjecting the sheet to the action of heat during the continuance of the drawing operation.

7. The method of forming a sheet of glass, which consists in preparing a mass of molten glass, and drawing the glass therefrom in sheet form, the drawing force being simultaneously applied in the direction of the sheets length and in the directions of its two edges, and subjecting the sheet to the action of heat during the continuance of the drawing operation.

8. The method of forming a sheet of glass, which consists in preparing a mass of molten glass, and drawing the glass therefrom in sheet form, the drawing force being simultaneously applied in a vertical direction and transversely of the sheet, and subjecting the sheet to the action of heat during the contin uancc ol' the drawing operation.

9. The method of forming a sheet of glass, which consists in preparing a mass of molten glass, and drawing the glass therefrom in sheet form, the drawing force being si1nulta neousiy applied in the direction of the top and edges of the sheet, and subjecting the sheet to the action of heat during the continuance ol' the drawin operation.

10. The method offorming a sheet of glass, whie h consists in preparing a mass of molten glass, continuously drawing a sheet of glass therefrom in the direction of the sheets length, and continuously drawing the molten glass in the direction of the sheets edges.

11. The method of forming a sheet of glass, which consists in preparing a mass of molten ill glass, tt litilltuntsl) thawing a sheet ol' glass therelroni in the direction the length and also in the diret'tion ol its edges while maintaining the heat in the drawn sheet high enough to prevenl t'raelting during the draw iug operation.

IL. in an appzu'atus l'or drawing sheetglass, the combination ol a receptacle lol' molten glass, a bait for drawing the glass in sheet l'orm therefrom, and revolving means counteracting the tendency ol the sheetv to narrow and draw to a rod or thread.

1.3. In an apparatus [or d|'.-i\\'ing sheet glass, the combination ol' a receptacle for molten glass, a bait for drawing the glass in sheet form therefrom, and means also drawing molten glass from said receptacle in the direction of the edges of the sheet, whereby said bait and said means draw a sheet of uniform width.

14. In an apparatus for drawing sheetglass, the combination ol a receptacle for molten glass, a bait for drawing the glass in sheet l'orm therel'rom, and upwardly and outwardly drawing means adjacent to the ends of the bait when the latter is in place in the molten glass.

15. In an apparatus for drawing sheetglass, the combination of a receptacle for molten glass, a bait, and means moving the. bait away from said receptacle to draw a sheet, with a plurality ot drawing devices acting to draw glass from said receptacle outward from the edges of the sheet drawn by the bait.

lti. In an apparatus for drawing sheetglass, the combination with a receptacle for molten glass, a bait, aml means withdrawing said bait from said receptacle to form a sheet, of drawing devices located one adjacent to ach edge of the sheet and serving to draw molten glass from said receptacle to lorm the edge portions ol' the sheet.

17. In an apparatus for drawing sheetglass, the combination with a receptacle for molten glass, a bait, and means withdrawing said bait from said receptacle to l'orm a sheet, ol' two drawing devices located one adjacent to each edge of the sheet at its bottom and serving to draw molten glass from said receptacle to form the edge portions of the sheet.

18. In an apparatus for drawing sheetglass, the combination with a receptacle lor molten glass, a bait, and neans withdrawing said bait from said receptacle to l'orm a sheet, of two drawing devices located one adjacent to each edge of the sheet and engaging the molten glass in said receptacle and serving to draw the glass therefrom to term the. edge portions of the sheet.

19. In an apparatus for drawing shectglass, the combination with a receptacle for molten glass, a bait and means withdrawing said bait from said receptacle to form a sheet, of two revoluble bodies located one adjacent sheet's to each edge of the sheet at its bottom and means revolving said bodies in opposite directions.

Ztl. ln an apparatus lor drawing sheetglass, the combination with a receptacle for molten glass, a l ait and means withdrawing said bait from said receptacle to form a. sheet, of two revoluble bodies located one adjacent to each edge of the sheet at its bottom and engaging the glass in said receptacle, and means revolving said bodies in opposite directions.

21. In an apparatus for drawing sheetglass, the combination of a receptacle for molten glass, a bait, and means withdrawing said bait l'roln the receptacle to form a sheet, of two rollers located one adjacent to each edge of the sheet near its bottom, and means revolving said rollers in opposite directions.

2'2. In an apparatus for drawing sheetglass, the combination of a receptacle for molten glass, a bait, and means withdrawing said bait from the receptacle to form a sheet, ol two rollers located one adjacent to each edge of the sheet near its bottom and having axes transverse to the plane of the sheet drawn by the bait, and means revolving said rollers in opposite directions.

23. In an apparatus for drawing sheetglass, the combination with a receptacle containing molten glass, a bait, and means withdrawing the bait from the receptacle to form a sheet, of two rollers revoluble on axes transverse to the sheet, the lower part of the peripheries of said rollers being immersed in the molten glass adjacent to the ed es of the sheet being drawn, and means revolving said rollers in opposite directions.

.34. In an apparatus for drawing sheetglass, the combination with a receptacle containing molten glass, a bait, means withdrawing said bait from the receptacle to form a sheet of glass, and filling or supply conduits or openings for the entrance of molten glass into said receptacle adjacent to the edges of the sheet being drawn.

25. In an apparatus for drawing sheetglass, the combination with a receptacle containing molten glass, a bait, means withdrawing said bait from the receptacle to form a sheet of glass, means counteracting the tendency of the sheet to narrow during drawing operation, and filling or supplv conduits or o enings for molten glass into said recepta- (il adjacent to the edges of the sheet being drawn.

26. In an apparatus for drawing sheetglass, the combination with a receptacle containing molten glass and having two filling or supply conduits or openings, of a bait interposable in the glass in said receptacle between said conduits or openings, and means withdrawing the bait from the receptacle to form a sheet of glass.

'27. In an apparatus for drawing sheetglas the t'tllllltltlillitlll with a |'t(tlll:tt'lt eon" taining' molten glas til it lutii. means witle drawing aid hait l roni the rereptaele toj form a sheet. rollers revolulile on axes tran j verse to the plane ol said sheet, means re volving said rollers in opposite direelions.

glass from said reeeptaele in sheet l'orm longttudmallv of the sheet, deviees drawing the i glass from the reeeptaele in the direetion of the edges of the sheet and independent o eri ating meehanisms for said means and dent-es.

30. In an apparatus l'or drawing sheet.-

glass, the eomlnnation with a reeeptaele eon t aining molten glass, of a hait for drawing a sheet of glass from said reeeptaele, means also drawing glass from the reeeptaele to form the. edge portions of the sheet. and independent operating meehanism for said hait and means, said meehanisms heing eapahle of operation at variable speeds.

3]. In an apparatus for drawing sheet glass, the combination of a reeeptarle eontaining molten glass, a cover for said reeep taele having a depressed eentral portion and elevated end portions, and a slot extending across said depressed portion and into said elevated end portions.

32. 111 an apparatus for drawing sheet glass. the eotnhination ol' a reieptaele eon taining' molten glass means I'or drawing a. sheet ol glass therelronu and means draw mg the glass to I'orni the edge poliltitts ol' the sheet wherelrv it is held to unilorm width.

3? In an apparatus for drawing sheetglass, :1 reeeptarle eontaining molten glass, means for drawing glass therel'rom in sheet term in a longitudinal direction, and means simultaneously drawing and st retehing the glass laterally.

34, la an apparatus for drawing sheetglass, at reeeptaele eontaining molten glass. means for drawing glass therel'rom in sheet form in a longitudinal direction, and a pluralit oi surl'aees drawing glass from said roeeptaele to form the side portions of the sheet and simultaneously stretching the sheet laterally.

3:3. ln an apparatus for drawing sheetglass, at reeeptaele containing molten glass, means drawing glass therefrom in sheet form in a longitudinal direction. means simultaneously drawing glass from said receptacle and stretehing the sheet in a lateral direction, and devices whereby said last-named 3. means may be operated at variable speeds.

36, In an apparatus for drawing sheetglass, a reeeptaele containing molten glass, means drawing glass therefrom in sheet form, two surfaces simultaneously drawing glass from said reeeptaele to form the lateral port tions of the sheet. and stretching said sheet, and means for eoohng the sheet as drawn.

In testimony whereof I have signed this speeilieation in the presence of two suhserib ing witnesses.

IRVING \V. ((HJBURN,

\Yitnesses:

THOMAS MCGOUGH, J. W. ROWLAND. 

